<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
  <div class="blockOut">
    <div class="block rotate1"></div>
    <div class="text">
        50%
    </div>
</div>

</body>
<style>
    .block {
      width: 200px;
      height: 200px;
      border-left: 10px solid red;
      border-top: 10px solid red;
      border-right: 10px solid gray;
      border-bottom: 10px solid gray;
      border-radius: 50%;
      box-sizing: border-box;
      position: absolute;
      top: -50%;
      transition: all ease 0.8s;
    }

    .blockOut {
        width: 200px;
        height: 200px;
        /* background: #ddd; */
        position: relative;
        overflow: hidden;
    }

    .block.rotate1 {
        transform: rotate(-45deg);
    }

    .text {
      text-align: center;
      top: 15%;
      position: absolute;
      width: 100%;
    }
</style>
</html>